I gave very recently a short presentation at my
institution on various options regarding cluster
architecture and "single node" architecture.
It seemed that from current pricing in Canada,
and for very memory intensive, but coarsely granular problem
the most bang for the buck is NOT using P4's.
I based my speculations on the STREAM data mostly, showing
that P4s with RDRAM are only 2-2.5 times faster then
well configured el cheapo clones, but cost 5-6 times as
much per node.
It was received only "so-so", mostly because people
almost like did not like to see that you can get 256GB of RAM,
256 processors for 256K (Canadian!= $USD 160K) - and each node sustains 50
MFLOPS on out-of-cache computations.
My viewpoint (formed partially from following this group)
was that one should buy on the cheap side, like above
and wait a bit with P4. Or go straight to alpha with 4GB
per CPU and large caches :-)
Cheers,
Marcin Kolbuszewski